General Operation

This unit is a microprocessor that monitors the oxygen sensor voltage and, based upon the mode of operation, generates an output control signal for the carburetor mixture control (MC) solenoid on 4-150 engines or stepper motor on 6-258 engines.
If the system is in the closed loop mode of operation, the air/fuel mixture will be varied according to the oxygen content in the exhaust gas and current engine operations.
If the system is in the open loop mode of operation, the air/fuel ratio will be based on a predetermined value that is determined upon several engine operating parameters.